Age-aware multimetric MRI assessment of patellofemoral dysplasia in a symptomatic nine-year-old girl without documented dislocation: A case report

Patellofemoral symptoms in children require age-aware interpretation because trochlear and patellar morphology change during growth and several commonly used magnetic resonance imaging (MRI) thresholds were derived from adults. We report a 9-year-old girl with anterior knee pain and gait disturbance, without trauma or documented patellar dislocation. MRI showed a shallow trochlear groove (trochlear depth, 1 mm) and a widened sulcus angle (164°), together with Wiberg type II patellar morphology and an Insall–Salvati ratio of 1.3. The latter 2 findings were interpreted as contributory rather than independently diagnostic because of pediatric variability. The educational value of this case lies in integrating multiple concordant measurements, explicitly acknowledging age- and technique-related limitations, and avoiding uncritical transfer of adult cutoffs to a skeletally immature patient. MRI can identify a structural predisposition before a documented dislocation and support an individualized, growth-respecting management strategy.